湖北省湖泊大型底栖动物群落结构及水质生物学评价

Macrozoobenthic community structure and bioassessment of water quality of shallow lakes in Hubei province

大型底栖动物是湖泊生态系统的重要生物类群，在生态系统物质循环和能量流动中起着重要作用。底栖动物具有生命周期长、迁移能力较弱、对环境变化反应敏感等特点，可有效指示湖泊生态系统的健康状况。湖北省是我国淡水湖泊分布最密集的区域之一，湖泊总面积为3025 km2。近年来，伴随着工农业、养殖业及城市化的快速发展，富营养化已成为本地区湖泊面临的一个主要环境问题，并可能直接影响大型底栖动物的群落结构。目前关于本地区湖泊大型底栖动物群落的研究还较少，为此本研究对湖北省27个浅水湖泊底栖动物进行了调查，并对水质状况进行生物学评价。共采集到底栖动物40种，隶属于4门7纲18科，其中寡毛类5种，摇蚊幼虫16种，软体动物双壳类4种、腹足类8种。霍甫水丝蚓（Limnodrilus hoffmeisteri）、苏氏尾鳃蚓（Branchiura sowerbyi）、花翅前突摇蚊（Procladius choreus）、中国长足摇蚊（Tanypus chinensis）、多巴小摇蚊（Microchironomus tabarui）及铜锈环棱螺（Bellamya aeruginosa）是本地区湖泊最常见的种类。所调查湖泊底栖动物平均密度为32~1243 ind·m-2，其中12个湖泊密度低于200 ind·m-2，摇蚊幼虫和寡毛类对密度的贡献较大，以摇蚊幼虫占优势的湖泊有19个。底栖动物平均生物量为0.034~460.7 g·m-2，生物量低于50 g·m-2的湖泊数量最多（19个），软体动物占优势的湖泊有16个，摇蚊幼虫和寡毛类占优势的湖泊数量共11个。各湖泊底栖动物物种数为3~14种，Margalef指数为0.71~2.33，Simpson指数为0.69~0.85，Shannon-Wiener为0.78~2.13，Spearman相关性分析结果显示物种丰富度和三种多样性指数与湖泊面积呈显著正相关。BI（Hilsenhoff生物指数）评价结果显示共11个湖泊为一般和轻度污染（6.01~7.44），中度污染湖泊数量为13个（7.57~8.47），长湖（8.52）、上津湖（8.65）和玉湖（8.50）处于重污染状态。

s：Macrozoobenthos are an important component and play crucial roles in nutrient cycling and energy flow in lake ecosystems. Their relative longevity, general sedentary and variable sensitivity to pollution make them good indicators of lake ecosystem health. In Hubei province, there are numerous floodplain lakes, with a total area of 3 025 km2. However, with the development of extensive industry, agriculture, fishing and urbanization in recent decades, many lakes in this area have undergone eutrophication, exerting great pressures on macrozoobenthos. However, few studies have been conducted on macrozoobenthic assemblages in these lakes. In this study, we carried out an investigation on macrozoobenthos of 27 shallow lakes in Hubei Province, and lake water quality was assessed based on the characteristics of the macrozoobenthic assemblages. A total of 40 macrozoobenthic taxa belonging to 4 phylum 7 classes and 18 families were recorded from quantitative samples, including 5 oligochaetes, 16 chironomids, 4 bivalves and 8 gastropods. Limnodrilus hoffmeisteri, Branchiura sowerbyi, Proclakius choreus, Tanypus chinensis, Microchironomus tabarui, Bellamya aeruginosa showed high occurrence in these lakes. Average abundance ranged from 32 to 1 243 ind·m-2 with 12 lakes lower than 200 ind·m-2, chironomids and oligochaetes dominated the community in abundance. Average biomass ranged from 0.034 to 460.7 g·m-2 with 19 lakes lower than 50 g·m-2. The biomass of macrozoobenthos were dominated by molluscs in 16 lakes, and dominated by chironomids and oligochaetes in 11 lakes. Species richness ranged from 3 to 14 taxa, Margalef index varied between 0.71 and 2.33, and the minimum/maximum values of Simpson and Shannon-Wiener indices were 0.69/0.85 and 0.78/2.13, respectively. Species richness and three diversity indices were significantly and positively correlated with lake surface area. Hilsenhoff biotic index （BI） indicated that 11 lakes were lightly polluted （6.01-7.44）, 13 lakes were moderately polluted （7.57-8.47）, and Changhu （8.52）, Shangjinhu （8.65） and Yuhu （8.50） were heavily polluted.